It has typically been known that an exhaust gas purifying device provided is in an exhaust pipe of an engine so that particulate matters (PM), i.e., particulate substances contained in exhaust gas that causes black exhaust, thereby preventing discharge of the PM into the atmosphere. The exhaust gas purifying device is generally provided with a soot filter for capturing PM and an oxidizing catalyst for oxidizing dosing fuel (e.g., diesel oil) to generate heat, the soot filter and the oxidizing catalyst each being covered by a cylindrical case (Patent Literature 1).
The cases are separable. When ash and the like accumulated on the soot filter are cleaned, the cases are disassembled and the case housing the soot filter is removed for maintenance.